| 摘要 |
A rotor (20, 10) of an electric motor includes a hollow rotation shaft (21, 120) supported by a housing (1, 11) to be rotatable relative to the housing, a back yoke (22, 121) fitted to an outer peripheral surface of the hollow rotation shaft (21, 120) and integrally rotating with the hollow rotation shaft, the back yoke (22, 121) including a cylindrical form, a plurality of permanent magnets (23, 122) arranged at the back yoke (22, 121) at even intervals in a circumferential direction of the back yoke, and a plurality of projecting portions (22e, 21 e, 121 e) formed at one of the back yoke (22, 121) and the hollow rotation shaft (21, 120), each of the plurality of projecting portions (22e, 21 e, 121 e) via which a magnetic path is formed from the back yoke (22, 121) to the hollow rotation shaft (21, 120). |
